EP2311671B1 - Valve for a pressurised air assembly of a commercial vehicle - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a valve in spool design for a compressed air system of a commercial vehicle. In particular, the valve is a lift axle valve or a lift-lowering valve in spool design.

STATE OF THE ART

Valves for a commercial vehicle's compressed-air system, such as a lift axle valve or a lift-and-lower valve, are exposed to high pneumatic pressures so that they can be designed for pressures of, for example, 8.5 bar, 12.5 bar, 15 bar or 20 bar. In the following, the state of the art and the invention will be described by way of example with reference to a lift axle valve, wherein more diversified prior art are known to other valves for a compressed air system of a commercial vehicle, such as a lift-lower valve, valve type and the invention also such otherwise arbitrary Valves in spool design includes.

A system for motor vehicles with air suspension and a Liftachsventil is known from the prospectus of the applicant with the name "INSTALLATION INSTRUCTIONS ILAS-E" with the publication notice 009 352 061 St. 1 / TS / 09.00 Heidelberg. A similar plant is also in the Fig. 1 and 2 played. The system has a supporting axle supported on supporting bellows and a lifting axle supported on bellows. The lift axle also has a lifting bellows with which it can be raised and lowered. The system includes a Liftachsventil, which is designed here as a 5/2-way valve. The lift axle valve points in a housing a control piston which is designed to be displaceable against the force of a spring in the housing. Connected to the control piston is a piston rod which carries a series of seals according to the slide design, in order to connect lines connected to one another or to close off or vent one another. In the brought about by the spring position of the control piston, in which therefore the control chamber is not ventilated, the lift bellows of the lift axle is vented, which has a lowering of the lift axle result. This corresponds to the safety thought that in case of failure of the electrical supply, the safe state, ie a lowered lift axle, to be achieved. In this position, on the other hand, the supporting bellows of the support shaft are connected to the bellows of the lift axle, so that via an upstream level control valve of the loading of the respective vehicle corresponding pressure is consistently controlled in the bellows and the bellows. The lift axle valve used can be controlled electrically via a solenoid valve. For this purpose, the solenoid valve of the Liftachsventils has a connection to the reservoir, so that it is supplied with compressed air from the reservoir. The solenoid valve has its own vent port and is designed and arranged so that it shuts off the supply port in the non-energized state by the force of a spring and vents the control chamber of the control piston. The solenoid valve responds to an electrical signal, so that the axle lift valve is electrically switchable as a result of this electrical signal via the solenoid valve. This corresponds to the general development direction of valves for motor vehicles, in which electrical signals are generated, processed and forwarded via an EBS, an ABS or another ECU in order to achieve corresponding switching states.

EP 0 830 958 B1 discloses a lift axle valve in spool type, in which an interior of a metallic housing is formed with a bore, so that it is bounded by a cylindrical inner surface. Control edges of a spool with sealing elements slide along this cylindrical inner surface to produce different operating positions of the spool valve. The interior passes over a step to another cylindrical inner surface of the housing with an enlarged diameter. Here, a sleeve is inserted into the interior, which is referred to in the document as an insert body. A sealing of the insert body relative to the cylindrical inner surface via three radial seals between which holes pass through the sleeve radially, over which formed between the spool and the insert body, axially closed by the seals control chambers with terminals of the housing are connectable.

DE 44 16 280 C1 relates to a level control valve with a two-part injection molded plastic housing. DE 199 23 456 C5 discloses the use of a fiber reinforced polyamide plastic for a housing of a level control valve. Further prior art relating to a valve constructed as a lifting axle valve in slide construction is made DE 10 2004 050 194 B3 known.

OBJECT OF THE INVENTION

The present invention has for its object to provide a valve, in particular a Liftachsventil or a lift-lower valve, for a motor vehicle, which is simplified in terms of manufacturing and / or assembly and disassembly, has lower material costs and / or has a lower weight ,

SOLUTION

The object of the invention is achieved with the features of independent claim 1. Further embodiments of a valve according to the invention will become apparent from the dependent claims 2 to 18.

DESCRIPTION OF THE INVENTION

Conventionally, housing for valves for a compressed air system of a commercial vehicle made of metal, in particular steel or aluminum, produced. It is possible that such housing are made of a solid material, with a high-volume associated with a high use of materials and production costs by exciting processing from a large-volume semi-finished a small-volume housing is worked out. Alternatively, the housings used are made of cast metal housings. Although a production of housings deviating from this plastic in other fields has been known for many years, the invention proposes for the first time that a housing of a valve for a compressed air system of a commercial vehicle is formed with plastic. In this case, in particular a plastic injection molding process can be used for the production of the housing.

The present invention precludes the prejudice of those skilled in the art that the pressure-conducting valve must be made of metal to ensure mechanical strength. Furthermore, the invention has surprisingly found that a production of the valve with eventual Ports, vents, control, piston and Überertrittskammern, channels and associated components in a manufacturing process for plastic, in particular in an injection molding, is possible.

On the other hand, the invention takes into account that the housing of the valve, which is formed with plastic, advantageously also over the entire temperature range to which a motor vehicle is exposed, for example, with temperature changes from minus 40 ° C up to plus 80 ° C, can be used without that a material failure, for example, as a result of cracking, embrittlement of the plastic or the like results or functional impairments, for example, due to different thermal expansions of functional surfaces of adjacent components with close tolerances are to be expected.

While the person skilled in the art, prior to the filing date of the present invention, has assumed that a spool of a spool valve must be moved in an interior with a cylindrical inner surface, the invention has further recognized that an interior having a frusto-conical interior surface is also used in the valve of the present invention can. This has the result, for example, that the interior and the frusto-conical inner surface can be molded into the plastic housing via an at least partially frusto-conical core, which can represent a significant simplification of the production. In a comparable manufacturing an interior with a cylindrical inner surface deviating from the present invention, a removal of a then cylindrical core would only be possible if in this area the housing would be divided with a dividing plane which extends through the longitudinal axis of the valve. In contrast, when using the frusto-conical inner surface demolding done by a frusto-conical core is simply pulled out of the housing after the solidification of the material. Such a housing is also advantageous because of the u. U. not divided training of the housing, at least in the region of the frusto-conical inner surface, the assembly is simplified and a parting line in the division plane, which could affect the function of the valve and may require additional sealing measures is avoided.

Furthermore, the invention has recognized that the direct interaction between the frusto-conical inner surface and the spool is not functional, since this could cause sealing problems especially in the control edges and / or as a result the variable contact pressure between the inner surface and the sealing element in the region of a control edge could lead to increased wear.

According to the invention, at least one sleeve is inserted into the interior space with a frusto-conical inner surface. The sleeve forms or limits radially inwardly a control chamber, which is connected via at least one radial passage recess of the sleeve with at least one radially outwardly of the sleeve arranged connection or a vent. Thus, the sleeve can provide the surface that interacts with the control and associated sealing elements. It is possible that a sleeve is used in the context of the invention according to the insert body according to EP 0 830 958 B1 , which is responsible for several different connections and control rooms. It is also possible that several sleeves find use that can be identical or are designed differently, for example, with the same diameters, but different axial extents or different diameters and axial extents. As a result of the frusto-conical inner surface, within which at least one sleeve is arranged, results radially outwardly from the at least one sleeve, a gap which is formed, for example circumferential in the circumferential direction, but in the direction of the longitudinal axis of the spool forms a variable gap height.

In order to be able to ensure the function of the valve in the valve type despite the variable gap height between the sleeve and the truncated cone-shaped inner surface, identical sealing elements are supported on the end faces of the at least one sleeve. These interact radially inwardly with the spool to interact to close adjacent control spaces in selected positions of the spool, while in other positions of the spool a connection is created between the adjacent control spaces past the sealing elements, for example by suitable crossing grooves in the spool.

Even if identical sealing elements are used, these sealing elements accomplish radially outwardly a seal against the frusto-conical inner surface of the housing. Here, an interpretation of the elasticity of the sealing elements (and the choice of the geometry of the same) such that differences in diameter due to the opening winding of the truncated cone are compensated. Because different sealing elements do not have to be used for different diameters, which requires careful selection during assembly of the valve would require, the variety of components can be reduced and the assembly can be simplified.

Finally, the embodiment of the invention allows the formation of the housing at least partially with plastic with simple production possibility of the housing with the use of a frustoconical core and use of a "sleeve technology" to form a control slide.

In a further embodiment of the invention find in the valve two or more sleeves insert, have the same diameter. Between the two or more sleeves (each) a sealing element is interposed, wherein intermediate sealing elements and supported on the end faces sealing elements are constructed identical. In this case, the frusto-conical inner surface has an extension in the direction of the longitudinal axis, which is greater than the sum of the extensions of the sleeves in the direction of the longitudinal axis. In this way it is possible that the formation of a multi-way valve and / or multi-position valve is possible with the use of the housing made of plastic and manufacturing the same with a frusto-conical inner surface when manufactured by a frusto-conical core.

According to a further proposal of the invention, the variety of components can be further reduced by two or more identical sleeves are used in the valve according to the invention.

As the plastic for the housing may be selected any plastic material which, for example, in terms of mechanical properties, resistance to exposure to the passed through the valve, possibly contaminated fluids, the exposure of the outer surface, for example, with dirt, the vibrations acting on the valve and the like is selected. Here, the housing or housing parts can consist exclusively of plastic. Also possible is the use of a composite formed with plastic. To name just a few examples, sleeves made of another material, for example metal, can be cast into the plastic where they then form functional surfaces. Also possible is the pouring of sleeves, which can then be used for passing through fastening bolts or when equipping them with a thread for screwing with mounting screws.

According to a particular proposal of the invention, the plastic with which the housing or parts of the housing are formed, reinforced with fibers. These fibers may be fibers of any length and any material. The use of glass fibers in the plastic has proved to be particularly effective. About u. U. also short glass fibers can be a targeted influence on the mechanical properties of the thus reinforced plastic, which constructively for this purpose, the density, length and / or orientation of the glass fiber can be specified. Here, the invention has recognized that in the use of (short) glass fibers in the plastic as possible no reworking of the housing or housing part should be made.

Basically, any shapes of the housing are possible, for example, a housing in which two in a first approximation "hat-like" housing parts via flanges, which are formed in the region of the Hutkrempen and a parting plane of the housing, which is oriented transversely to a longitudinal axis of the housing, connected to each other. In a further embodiment of the valve, however, the invention proposes that the housing is formed with a main housing, which, for example, is "pot-shaped" in a first approximation, and a lid closing the main housing is formed. With the main housing an interior of the housing is automatically predefined, in which the relevant valve elements, such as a valve spool, can be arranged. An assembly is also simplified for such a design of the housing by successively arranging the relevant components in said interior space of the main housing. If all relevant components are arranged in the interior, this can be completed via the lid. It is understood that in the main housing in addition to the opening which is closed by the lid, further openings may, for example, be arranged to form terminals, for example in a side wall and / or the bottom wall opposite the opening for the lid.

It is quite possible that for the housing formed with plastic a venting of the valve accordingly DE 10 2004 050 194 B3 is disposed in a bottom region of the valve and aligned with the longitudinal axis of the valve. However, such an embodiment may require that the valve has a bore extending through a main housing in the direction of the longitudinal axis, with a varying cross section, wherein in particular a cross section in the region of the venting of the valve may form an undercut. Such undercut can be avoided according to the invention, when a bottom portion of the housing with a closed bottom wall is formed, so that not the vent is arranged here. Rather, the venting of the valve is provided in a side region of the main housing. Thus, a central bore of the main housing, which serves in particular for receiving a valve spool, not formed as a through hole with said undercuts, but rather as a blind hole (possibly with additional transverse bores extending through the side walls of the main housing). As a result, under certain circumstances, the production of the housing of the valve can be made possible with plastic or the production can be simplified, for example by reducing the number of sliders or cores to be used for the injection molding process.

In a further embodiment of the invention, this proposes that the vent is formed with an insert made of plastic. This insert is fluidically connectable to a lateral recess, in particular a channel or a connection, of the main housing. It is also possible that the insert is at least partially insertable into a lateral recess of the main housing.

Preferably, the invention proposes to use an opening angle of the frusto-conical inner surface of 0.1 ° to 2.0 °, for example 0.2 ° to 1.0 °. Investigations by the applicant have shown that such an opening angle of the frusto-conical inner surface on the one hand ensures good demoulding of the core, but on the other hand can still be compensated with the elasticity of the sealing element.

On the other hand, the closed bottom portion of the main body due to the arrangement of the vent in the side region of the main housing can be used to a compression spring over which a spool of the valve is supported, not mandatory - as in DE 10 2004 050 194 B3 disclosed - must be arranged on the back of the control piston, but rather can be interposed between the bottom wall of the main housing and an end face of the spool, resulting in expanded structural design options.

While in principle the production of the main housing with any cores, core slides in one or more parts training is possible, the invention proposes in a further embodiment that an interior of the main housing is made with a core slider, which has at least one transverse to the longitudinal axis extension. To remove the To allow core slide with continuation nevertheless, in particular by sole movement of the core slide with extension along the longitudinal axis, a dimensioning of the wall thicknesses of the main housing, a choice of stiffness of the material used, the dimensioning of the at least one extension such that the core slide on a forced removal from the cooled plastic can be removed. Thus, an elastic expansion of the main housing is used to manufacture formed with the projections "undercuts" and still allow removal of a one-piece core slider.

While the lid in the simplest case only serves to close off the main housing, according to another proposal of the invention, the latter can also be used in a multifunctional manner by limiting the control space via which actuation of the valve takes place via a suitable control device.

It is also possible that the lid as a further function forms a receptacle for a solenoid valve, via which, for example, the pressure conditions in the aforementioned control chamber can be influenced.

In a further embodiment of this basic idea, the lid does not only accommodate the solenoid valve itself. Rather, in this case, the lid also forms a valve seat, on which comes in a closed position of the solenoid valve from the solenoid valve according to an electric actuation moving valve body to the plant.

A particular aspect of the invention is devoted to the connection of the lid to the main housing. While it is quite possible that a screwing of the lid to the main housing can be done with formation of a bore or thread for the purpose used at least one screw through the plastic itself or in the plastic cast other materials, sleeves or the like, the invention proposes according to a further embodiment, that the lid is connected without the use of a screw connection to the main housing.

For such an embodiment, the lid is clipped onto the main body. Such a Aufklipslösung takes into account the plastic used for the lid and / or main housing, wherein a spring element, which for the clipping and the generated detent or Locking connection is applied, may be formed directly from a resilient web or an elastic material portion of the lid made of plastic. On the other hand, a clipped lid is particularly easy to assemble. Also, the dismantling can be easily possible if, for example, a disassembly bevel is provided which solves the locking connection with the application of forces again. Preferably, however, such a simple disassembly is not desired. In this case u. U. a form-locking connection formed by the latching connection can be solved only with an additional tool. It is also possible that an additional securing device is provided, which comes after a connection of the lid to the main housing, possibly with a prior examination of this compound for proper connection and / or tightness effect. For example, the securing element can block the elastic degree of freedom of the locking element in the securing position.

For an alternative embodiment, the cover is connected via a bayonet connection with the main housing, which is also very easy to assemble and disassemble.

In the context of the invention, a seal between the lid and the main housing via a sealing element, which is elastically clamped between the lid and the main housing. For example, such a sealing element is an O-ring. A multifunctional use of this sealing element is made possible when this sealing element is responsible in addition to the seal between the cover and the main housing, to produce the axial securing of the sleeves and / or the axial bias of the sealing elements. If the sleeves or a support body for these sleeves in addition to the main housing, for example, radially inwardly of this, on the sealing element, can be applied to the sleeves with the preparation of the connection between the cover and the main housing via the sealing element, an elastic spring force, which then in the interior, possibly under limited displaceability due to the elasticity of the intermediate sealing elements hold. With an axial compression of the interposed between the sleeves sealing elements, the sealing elements can also be pressed outwards, so that the sealing elements are pressed against the inner surface despite the frusto-conical.

Usually, the production of valves with a different number of terminals, for example, as a result of the valve to be fed circuits, bellows, bellows or lift bellows and / or axis. According to the invention, the manufacture of the valve with a different number of connections but also be carried out in that the number of connections can be specified via additional cores. Thus, for example, finds an injection molding with plastic insert in the same basic form with a different number of additional or removable cores, the number of connections of the valve created can be varied while maintaining all manufacturing steps and use the same basic form.

Advantageous developments of the invention will become apparent from the claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the introduction to the description are merely exemplary and can come into effect alternatively or cumulatively, without the advantages having to be achieved by embodiments according to the invention. Further features are the drawings - in particular the illustrated geometries and the relative dimensions of several components to each other and their relative arrangement and operative connection - refer. The combination of features of different embodiments of the invention or of features of different claims is also possible deviating from the chosen relationships of the claims and is hereby stimulated. This also applies to those features which are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different claims. Likewise, in the claims listed features for further embodiments of the invention can be omitted.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1

zeigt schematisch eine Luftfederungsanlage gemäß dem Stand der Technik mit abgesenkter Liftachse.

Fig. 2

zeigt schematisch die Luftfederungsanlage gemäß Fig. 1 für angehobene Liftachse.

Fig. 3

zeigt schematisch ein elektrisch ansteuerbares Ventil, hier ein Liftachsventil.

Fig. 4

zeigt ein Ventil in Ausbildung als Liftachsventil in einem Schnitt B-B (vgl. Fig. 9) in einer Schaltstellung, die zu einer abgesenkten Liftachse führt.

Fig. 5

zeigt das Liftachsventil in einem Schnitt mit einer versetzten Schnittführung A-1 - A-1 bzw. A-2 - A-2 (vgl. Fig. 9).

Fig. 6

zeigt das Liftachsventil in einem Schnitt entsprechend Fig.4, aber in einer Schaltstellung, welche einer angehobenen Liftachse entspricht.

Fig.7

zeigt das Liftachsventil in einem Schnitt entsprechend Fig.5, aber in einer Schaltstellung, die einer angehobenen Liftachse entspricht.

Fig. 8

zeigt eine räumliche Ansicht des Liftachsventils gemäß Fig. 4 bis 7.

Fig. 9

zeigt eine Draufsicht auf das Liftachsventil gemäß Fig. 4 bis 8, aus welcher die unterschiedlichen Schnittführungen ersichtlich sind.

Fig. 10

zeigt eine räumliche Ansicht von oben auf ein Detail des Liftachsventils mit einem über eine Rastverbindung an einem Hauptgehäuse gehaltenen Deckel.

Fig. 11

zeigt den Deckel mit Hauptgehäuse gemäß Fig. 10 in einer räumlichen Ansicht schräg von unten.

Fig. 12

zeigt eine räumliche Ansicht eines Details eines als Liftachsventils ausgebildeten Ventils mit einem Deckel, welcher über einen Bajonett-Verschluss mit einem Hauptgehäuse verbunden ist.

Fig. 13

zeigt den Deckel mit Hauptgehäuse gemäß Fig. 12 in einer räumlichen Ansicht schräg von unten.

Fig. 14

zeigt ein weiteres als Liftachsventil ausgebildetes Ventil mit einem Deckel, welcher über einen Bajonett-Verschluss mit zusätzlichen Haken mit einem Haupt- gehäuse verbunden ist, in einer räumlichen Detailansicht schräg von unten.

Fig. 15

zeigt den Deckel mit Hauptgehäuse gemäß Fig. 14 in einer räumlichen Detail- ansicht schräg von unten.

Fig. 16

zeigt eine weitere Ausführungsform eines als Liftachsventils ausgebildeten Ventils mit einem Deckel, der über radiale und tangentiale Rasthaken mit einem Hauptgehäuse verbunden ist, in einer räumlichen Detailansicht schräg von oben.

Fig. 17

zeigt den Deckel mit Hauptgehäuse gemäß Fig. 16 in einer räumlichen Detail- ansicht schräg von unten.

Fig. 18

zeigt die Verbindung zwischen einem Deckel und einem Hauptgehäuse über eine Rastverbindung in einem Längsschnitt mit einem Sicherungselement, welches sich in einer nicht gesicherten Stellung befindet.

Fig. 19

zeigt den Deckel mit Hauptgehäuse gemäß Fig. 18, wobei sich das Sicherungs- element in der gesicherten Stellung befindet.

Fig. 20

zeigt eine weitere Verbindung eines Deckels mit einem Hauptgehäuse über eine Rastverbindung in einem Längsschnitt, wobei sich das Sicherungselement in einer nicht gesicherten Stellung befindet.

Fig. 21

zeigt den Deckel mit Hauptgehäuse und Sicherungselement gemäß Fig. 20, wobei sich das Sicherungselement in der gesicherten Stellung befindet.

In the following the invention will be further explained and described with reference to preferred embodiments shown in the figures.

Fig. 1

schematically shows an air suspension system according to the prior art with lowered lift axle.

Fig. 2

schematically shows the air suspension system according to Fig. 1 for raised lift axle.

Fig. 3

schematically shows an electrically controllable valve, here a Liftachsventil.

Fig. 4

shows a valve in training as Liftachsventil in a section BB (see. Fig. 9 ) in a switching position, which leads to a lowered lift axle.

Fig. 5

shows the lift axle valve in a section with an offset cutting guide A-1 - A-1 and A-2 - A-2 (see. Fig. 9 ).

Fig. 6

shows the lift axle valve in a section accordingly Figure 4 but in a switching position which corresponds to a raised lift axle.

Figure 7

shows the lift axle valve in a section accordingly Figure 5 but in a shift position that corresponds to a raised lift axle.

Fig. 8

shows a spatial view of the lift axle valve according to Fig. 4 to 7 ,

Fig. 9

shows a plan view of the Liftachsventil according to Fig. 4 to 8 from which the different cuts are visible.

Fig. 10

shows a spatial view from above of a detail of the Liftachsventils with a latched connection to a main housing lid.

Fig. 11

shows the lid with main body according to Fig. 10 in a spatial view diagonally from below.

Fig. 12

shows a three-dimensional view of a detail of a trained as Liftachsventils valve with a lid which is connected via a bayonet closure with a main housing.

Fig. 13

shows the lid with main body according to Fig. 12 in a spatial view diagonally from below.

Fig. 14

shows another trained as Liftachsventil valve with a lid which is connected via a bayonet closure with additional hooks with a main housing, in a detailed view obliquely from below.

Fig. 15

shows the lid with main body according to Fig. 14 in a detailed spatial view diagonally from below.

Fig. 16

shows a further embodiment of a lift axle valve designed as a valve with a lid which is connected via radial and tangential latching hooks with a main housing, in a detailed view obliquely from above.

Fig. 17

shows the lid with main body according to Fig. 16 in a detailed spatial view diagonally from below.

Fig. 18

shows the connection between a cover and a main housing via a latching connection in a longitudinal section with a securing element, which is in an unlocked position.

Fig. 19

shows the lid with main body according to Fig. 18 , with the fuse element in the secured position.

Fig. 20

shows a further connection of a cover with a main housing via a latching connection in a longitudinal section, wherein the securing element is in an unlocked position.

Fig. 21

shows the lid with main body and fuse element according to Fig. 20 , wherein the securing element is in the secured position.

DESCRIPTION OF THE FIGURES

In the following, the invention will be explained with reference to a valve designed as lift axle valve. This exemplary selection of a lift axle valve is not intended to limit the present invention to this type of valve. Rather, the features of the invention are for any can be used otherwise, provided that this use is in a compressed air system of a commercial vehicle and designed in slider design.

Fig. 1 shows an air suspension system 1, as this example DE 10 2004 050 194 B3 is known. The central part of the air suspension system 1 is a Liftachsventil 2, which has an attached solenoid valve 3 and is thus electrically controlled. The control of the solenoid valve 3 via an electrical or electronic control unit 4 and an electrical control line 5, via which ultimately a magnet 6 of the solenoid valve 3 is energized or not energized. The magnet 6 is supported on a spring 7 and takes in non-energized state due to the bias of the spring in Fig. 1 shown closed position. The solenoid valve 3 has its own vent port 8.

The lift axle valve 2 has in its pneumatic part a main housing 9, in which a control piston 10 with a piston rod 11 slidably and sealingly slidably. The piston rod 11 is formed in a slide-type and has on its periphery a plurality of seals, which serve to produce or shut off corresponding line connections. The control piston 10 is supported on a spring 12. The spring 12 is located in a spring chamber 13, which is connected by means of a piston rod 11 passing through channel 14 to a vent port 15. The control piston 10 defines a control chamber 16.

The main body 9 of the pneumatic part of the lift axle valve 2 has a series of ports. At a connection 17, a reservoir 18 is connected via a supply line 19. Thus, supply air is between the two uppermost seals on the piston rod 11 of the Liftachsventils 2. Also, supply air is supplied via a branch line 20 to an inlet seat 21 of the solenoid valve 3. The magnet 6 forms an inlet valve 6, 21 with the inlet seat 21. The solenoid valve 3 has an outlet seat 22. The magnet 6 forms an outlet valve 6, 22 with the outlet seat 22. From a valve space 23 formed around the magnet 6, a line 24 leads to the control chamber 16 of the control piston 10. The outlet valve 6, 22 leads via the venting connection 8 into the atmosphere. In the position shown so the control chamber 16 is vented and the control piston 10 is due to the force of the spring 12 in its one position, which is referred to as venting position and in which the lift axle is lowered. For this purpose, a connection 25 is provided on the main housing 6 of the lift axle valve 2, from which a line 26 to a lift bellows 27 of a lift axle 28 leads. The line 26 and thus the lift bellows 27 is vented in this position via a branch channel 29, which is in communication with the channel 14. The venting of the lift bellows 27 corresponds to the lowered state of the lift axle 28. The lift axle 28 otherwise has spring bellows 30, which are ventilated or vented via a connection 31 and a line 32. Finally, the main housing 9 of the Liftachsventils 2 still has another terminal 33, to which a line 34 is connected, in which a level control valve 35 is arranged. It is understood that the level control valve 35 has a compressed air supply and on the other hand controls a modified pressure according to the load state, which passes via a line 34 connected to the line 36 in the support bellows 37 of a support shaft 38. In the line 34 after the level control valve 35, a pressure sensor (not shown) is usually arranged, which supplies an electrical signal corresponding to the pressure via a signal line 39 of the control unit 4, wherein the solenoid valve 3 switches depending on the signal.

Function and operation of the known air suspension system 1 according to Fig. 1 are thus understandable for a specialist. It is the venting position of the Liftachsventils 2 shown, that is, a position which results when the magnet 6 of the solenoid valve 3 is not energized. Since the lift bellows 27 is vented, the lift axle 28 is lowered. When the vehicle is partially empty or below the switching point, the control unit 4 controls via the control line 5 a corresponding signal to the solenoid valve 3, so that the magnet 6 is energized and switches to its other position. In this case, the outlet valve 6, 22 is closed and the inlet valve 6, 21 is opened, so that compressed air enters the control chamber 16. As a result, the control piston 16 and the piston rod 11 assume their other position, as in principle Fig. 2 is indicated. Thus, the lift bellows 27 is vented and lifted the lift axle 28, wherein the bellows 30 are vented.

While basically the transmission of the features explained below also to an embodiment of the lifting axle valve 2 according to the Fig. 1 and 2 is possible, the transfer of the features to any other embodiment of a Liftachsventils 2 is possible. For example, shows Fig. 3 a schematic diagram of a Liftachsventils 2 in which a terminal 17 is formed branched for supplying a supply pressure, so that two terminals 40, 41 are provided. The solenoid valve 3 is also formed in this case as a 3/2-way valve 42. The slide valve according to Fig. 1 and 2 is here designed as a 5/2-way valve 43, wherein the control line 24 of the pneumatically controlled 5/2-way valve 43 via the 3/2-way valve 42, depending on the signal in the control line 5 with a port 41, 40, so the supply pressure, is connectable or with the vent port 8. For vented control line 24 is the 5/2-way valve 43 in the in Fig. 3 effective switching position. In this, the 5/2-way valve 43 connects a vent port 15 with ports 44, 45, which are each connected to a lift bellows 27, while ports 46, 47, which are connected to Luftfederbälgen 30, via the 5/2-way valve 43 with a connection 33 which is in fluid communication with the level control valve 35. By contrast, in the other switching position with a pressurization of the control line 24, the terminals 46, 47 connected to the vent port 15, while the terminals 44, 45 are connected via the 3/2-way valve to the terminals 40, 41, so that here the supply pressure acts.

4 to 9 show an embodiment of a Liftachsventils 2, for which partially the same reference numerals are used as for the embodiments according to Fig. 1 to 3 if the components or constructive details marked with the reference numerals correspond constructively or functionally to a certain extent. In the Fig. 5 and 7 is an offset cut with sections A-1 - A-1 and A-2 - A2 chosen such that the partial sections each extend through the longitudinal axis of the individual terminals (see. Fig. 9 ).

The Liftachsventil 2 has a housing 48 which is formed with a cover 58 and a main housing 49. The main housing 49 is formed with a first housing part 50 and a second housing part 51, wherein the two housing parts 50, 51 abut each other in the region of a dividing plane 52 with sealing with flush inner surfaces. The housing parts 50, 51 are each formed such that they can be dug out of a mold in a direction which is oriented vertically to the dividing plane 52. In this case, the housing parts 50, 51 have a first, rough approximation, a convex outer contour of its cross section.

• eine Ausnehmung 59, im Bereich welcher der Entlüftungsanschluss 15 gebildet ist (vgl. Fig. 4),
• eine Ausnehmung 60 für einen Vorratsanschluss 17 zur Verbindung mit einem Vorratsbehälter 18 (Fig. 5),
• eine Ausnehmung 61 für einen Anschluss 33, welcher fluidisch mit dem Niveauregelventil 35 verbunden ist (Fig. 5),
• eine Ausnehmung 62 für einen Anschluss 31 zu dem Federbalg 30 (Fig. 5) und
• eine Ausnehmung 63 für einen Anschluss 25, der fluidisch mit dem Liftbalg 27 verbunden ist (Fig. 5).

The main housing 49 is in the in Fig. 4 illustrated in a first approximation U-shaped with a base leg 53 and two side legs 54, 55. The base leg 53 forms a divided in the region of the dividing plane 52 bottom wall 56, while the side legs 54, 55, also divided by the dividing plane 52 to order form a longitudinal axis 66 circumferential side wall 57. In the end regions of the side legs 54, 55 and the side wall 57, the main housing 49 forms an opening, which with the lid 58th is closed. Transverse to a longitudinal axis of the lift axle valve 2, the following recesses are introduced into the side wall 37 of the main housing 49:

• a recess 59, in the area which the vent port 15 is formed (see. Fig. 4 )
• a recess 60 for a supply connection 17 for connection to a reservoir 18 (FIG. Fig. 5 )
• a recess 61 for a connection 33, which is fluidically connected to the level control valve 35 ( Fig. 5 )
• a recess 62 for a connection 31 to the bellows 30 (FIG. Fig. 5 ) and
• a recess 63 for a connection 25, which is fluidically connected to the lifting bellows 27 ( Fig. 5 ).

For the illustrated embodiment, the terminals 17, 25, 31, 33 are each formed with inserts which are inserted, pressed or screwed into the recesses 60, 61, 62, 63 and have a secure quick-coupling mechanism for connection to the associated lines.

The main housing 49 has extensions or accumulations of material 64, 65 which are arranged on opposite sides of the longitudinal axis 66 of the Liftachsventils 2 and which are also divided by the dividing plane 52. In the extensions metallic sleeves 67, 68 poured or joined in this created recesses, which have parallel longitudinal axes. The sleeves 67, 68 are used to attach the Liftachsventils 2 to an adjacent component of the motor vehicle by a screw through the sleeves 67, 68 can be inserted, which can then be screwed to the adjacent component. In the main housing 49, an interior 69 is formed, with which all ports 17, 25, 31, 33 and the vent port 15 communicate. The interior space 69 is bounded by a blind hole 72 of the main housing 49, which widens away from the bottom wall 56 via two steps 70, 71 and whose longitudinal axis is oriented coaxially to the longitudinal axis 66. Even outside the steps 70, 71, the blind bore 72 is not hollow-cylindrical, but rather frusto-conical with a frusto-conical inner surface 131 is formed, the truncated cone opens away from the bottom wall 56, for example, with an opening angle of 0.1 ° to 2.0 °, for example. 0.2 ° to 1.0 °. In Fig. 5 above the step 70 extends in the blind bore 72 up to the upper end portion of the side wall 57 a formed with a plurality of elements valve body 73. The valve body 73 is formed for the illustrated embodiment with multiple sleeves 74a to 74e. The sleeves 74 have roughly a hollow cylindrical geometry, wherein in the outer circumferential surface of the sleeves 74 each center a circumferential groove 75 is introduced. The lateral surface of the sleeves 74 is dimensioned such that it can be inserted into the blind hole 72 while forming a slight play, which varies slightly as a result of the mentioned opening angle over the longitudinal axis 66 of the blind bore 72. At the first approximate annular end faces of the sleeves 74, these are in each case on an elastic sealing element 76, which causes both radially outwardly against the blind hole 72 a seal and radially inwardly against a spool 77 of the Liftachsventils 2. The closest to the Bottom wall 56 arranged sleeve 74 a is supported on such a sealing element 76 on the step 70, while between the mutually facing end faces of the sleeves 74 a, 74 b, 74 c, 74 d, 74 e a respective sealing element 76 is interposed. On the bottom wall 56 facing away from the end face of the sleeve 74 e, a support sleeve 78 is supported via a corresponding sealing element 76. The support sleeve 78 is formed for example with a deep-drawn sheet or a plastic body. The support sleeve 78 has a hollow cylindrical, possibly also slightly conical base body 79, the outer surface of which finds a snug fit in the blind hole 72 above the step 71. In the area of the step 71 of the main housing 49, the diameter of the support sleeve 78 is reduced over a step. The support sleeve 78 terminates in the sleeve 74e facing end portion with a transverse to the longitudinal axis 66 oriented collar 80 which rests with an annular end face on the sealing element 76 which is supported on the sleeve 74e. In the end region of the side wall 57, the cover 58 is connected to the main housing 49 via a connection mechanism which will be explained in more detail below. Between lid 58 and main housing 49 acts guided in a circumferential groove sealing element 81, for example, an O-ring. However, the sealing element 81 is supported only on a partial annular surface on a suitable mating surface of the main housing 49 in order to effect a seal. Another, radially inwardly disposed from the aforementioned part-annular surface partial annular surface of the sealing element 81 is - as from Fig. 5 seen - supported on the facing end face of the support sleeve 78. Thus, the sealing element 81 generates a spring force which presses the support sleeve 78 and the valve body 73 in the blind hole 72. In this case, the power flow from the sealing element 81 via the support sleeve 78, a sealing element 76, sleeve 74e, sealing element 76, sleeve 74d, sealing element 76, sleeve 74c, sealing element 76, sleeve 74b, sealing element 76, sleeve 74a, sealing element 76 to the level 70. An influence on the force relationships can be done in addition by a stage 82 of the support sleeve 78 comes to rest on the step 71, so that is predetermined by the distance of the step 82 of the collar 80, at which axial location along the longitudinal axis 66, the last sealing element 76 and thus the sleeve 74e is arranged.

• der Hülse 74a mit Ausnehmung 60 und dem Anschluss 17,
• der Hülse 74b mit der Ausnehmung 63 und dem Anschluss 25,
• der Hülse 74c mit der Ausnehmung 59 und dem Entlüftungsanschluss 15,
• der Hülse 74d mit der Ausnehmung 62 und dem Anschluss 31 und
• der Hülse 74e mit der Ausnehmung 61 und dem Anschluss 33.

The grooves 75 of the sleeves 74 are each in operative connection with a terminal, namely the groove 75th

• the sleeve 74a with recess 60 and the terminal 17,
• the sleeve 74b with the recess 63 and the terminal 25,
• the sleeve 74c with the recess 59 and the vent port 15,
• the sleeve 74d with the recess 62 and the terminal 31 and
• the sleeve 74e with the recess 61 and the terminal 33rd

The sealing elements 76 have sufficient radial elasticity to compensate for the conicity of the blind hole. In the valve body 73 is guided under sealing by the sealing elements 76 of the spool 77. The spool 77 has in the region of the operative connection with the sealing elements 76 has a cylindrical lateral surface, in which in the circumferential direction circumferential control grooves 83, 84 are introduced. Between the sleeves 74, the lateral surface of the spool 77 and the associated, on the end face of the respective sleeve 74 supporting sealing elements 76 each control chambers 132 are formed. Depending on the position of the control slide 77, individual sealing elements 76 can be bridged selectively via the control grooves 83, 84, so that adjacent control chambers 132 are connected to one another via the control grooves 83, 84. The control chambers 132 are each connected via a through-passage 133 with the sleeve 74 associated with the connection. The grooves 75 of the sleeves 74 are each connected via a radial bore with the peripheral, sealed by the sealing elements 76 control chamber 132 between the inner circumferential surface of the sleeves 74 and the outer circumferential surface of the spool 77. In the in the Fig. 4 and 5 shown upper switching position of the spool 77 is a connection between the terminals 31, 33 created via the control groove 83, while the control groove 84 provides a connection of the terminal 25 with the vent port 15. On the other hand creates in the lower switching position of the spool 77 according to Fig. 6 and 7 the control groove 83 a connection of the terminal 31 with the vent port 15, while the control groove 84 creates a connection between the terminals 17, 25.

The spool 77 is connected via a biased compression spring 85 in the direction of the position according to Fig. 5 and 6 applied. The compression spring 85 is in this case clamped between the bottom wall 56 and an end face 86. In order to allow a compact design despite large length of the compression spring 85, the end face 86 is displaced for the illustrated embodiment with a blind hole or stepped bore in the interior of the spool 77. In the end region facing away from the bottom wall 56, the control slide 77 forms the control piston 10, the diameter of which is preferably widened in relation to the diameter of the control slide 77 in the region of the sleeves 74. The spool 10 is guided under sealing by a sealing element 87 slidably into the base body 79 of the support sleeve 78 and defines a control chamber 88, which is further limited by the support sleeve 78 and the cover 58. The arranged on the side facing away from the control chamber 88 side chamber 89 may be vented to allow the movement of the control piston 10, for example by suitable branch channels 90 of the spool 77, which open into the spring chamber 91 below the spool 77, which is vented in a manner not shown. From the port 17, the supply pressure via the branch line 20 (see. Fig. 6 ) is guided through the side wall 57. This opens into the upper end side of the side wall 57, where the supply pressure is transferred into a stub 92, which is pneumatically connected to the inlet seat 21, which is formed by the cover 58. The tight pneumatic connection between the branch 20 and the stub 92 is made with the connection of the cover 58 to the main housing 49, wherein the junction between the branch line 20 and the stub 92 may be surrounded by a further sealing element 93. With the connection of the cover 58 to the main housing 49, the sealing element 93 is biased and pressed under sealing both against the cover 58 and against the main housing 49.

In the direction of the longitudinal axis 66, a blind hole-like recess 95 is introduced from above into the cover 58, into which the solenoid valve 3 can be inserted. For example, the solenoid valve may be screwed into a threaded recess 95. The solenoid valve 3 preferably has a valve body, which comes in a closed position for sealing engagement with the inlet seat 21. The solenoid valve 3 has an outlet seat 22 with associated vent port 8 according to the in the Fig. 1 and 2 illustrated embodiment. In addition, a standardized electrical connection 94 can be seen in the figures, via which the solenoid valve 3 can be electrically coupled to the control line 5. It is also possible that a vent of both the spring chamber 91 and the chamber 89 via a bore 96 of the support sleeve 78, which is connected via a branch channel 97 in the side wall 57 with the vent port 15 and the recess 59.

Analogous to the Fig. 1 and 2 the solenoid valve 3 is connected to the control chamber 88 in a manner not shown in the figures.

The vent port 15 is formed with a likewise made of plastic circular cover 98 with a first approximation T-shaped cross-section. The transverse leg of the T closes in this case the recess 59 of the main housing 49, wherein in the radially outer edge regions of the lid 98 locking elements 99 or a circumferential elastically deformable locking collar are provided, via which the lid 98 can be latched into suitable locking grooves of the main housing 49, wherein other , in the following explained in detail for the lid 58 connection techniques for the connection between the cover 98 and main housing 49 can be used. Supplementary sealing elements may be provided between the cover 98 and the main housing 49. The transverse leg of the T of the lid 98 has a plurality of through holes or slots 100 through which the venting can take place. The vertical leg of the T, which in the in Fig. 6 illustrated installation situation is oriented transversely to the longitudinal axis 66 of the Liftachsventils 2, is located on a vent body 101 or a vent diaphragm in the middle and supports it in the radial direction. The vent body 101 is formed in a first approximation T-shaped and rotationally symmetrical to the vertical leg of the T, wherein the vertical leg of the T of the vent body 101 snug fit recording under elastic bias in a radial bore 102 of the main housing 49, whereby the longitudinal axis of the vent body 101 in cooperation is fixed with the vertical leg of the T of the lid 98. The transverse leg of the T of the vent body 101 is elastically biased against a vent valve seat 103. If a pressure on the inside of the vent body 101, the transverse leg of the T is deformed so that the vent body 101 is pushed away from the vent valve seat 103 and a vent through the slots 100th can be done.

Depending on the number of lines and bellows to be connected, said connections can be made double, as in Fig. 8 can be seen. It is also possible that deviating from Fig. 8 the respective connections are formed only individually, but outside the Liftachsventils 2 a T-piece is used so that several lines can be connected to a port.

In particular, the cover 58, the main housing 49, the cover 98, the sleeves 74 and / or the spool 77 with the control piston 10 may be made of plastic, wherein the same or different plastics can be used for said components. It is also possible that a fiber-reinforced plastic is used in at least one of said components, for example, with short distributed in the plastic glass fibers. Such short fibers can be mixed in the extruder with the plastic material, which is preferably provided in granular form.

In the Fig. 10 to 17 different connection means 104a, 104b, 104c, 104d are shown for the components made of plastic. These are shown by way of example for the connection between cover 58 and main housing 49, wherein corresponding connecting devices can also be used for other components to be connected, in particular the connection of the cover 98 to the main housing 49.

According to the in 10 and 11 illustrated embodiment of the connecting device 104a has the cover 58 distributed over its circumference, in the direction of the longitudinal axis 66 downwardly oriented locking elements 105, which are formed with an elastic spring arm and a latching lug. The locking elements are deformed in the attachment of the cover 58 to the main housing 49 in the circumferential direction by the detents slide along the bevels formed by the main housing 49, which is associated with an elastic deformation of the spring arms in the circumferential direction. If the cover 58 is pressed against the end face of the side wall 57, with elastic loading of the sealing elements 51, 93, the latching lugs snap into locking grooves of the main housing 49.

For a modified, not shown embodiment, corresponding locking elements can be used, which are not deformed in this case, however, in the circumferential direction, ie along the edge of the cover 58, but radially outward. In this case, the locking lugs of the locking elements 105 with the snap-in radially inwardly into locking grooves of the main housing 49 a. It is understood that in the reverse configuration, the locking elements 105 may be formed by the main housing 49, while the associated locking grooves are formed in this case by the cover 58.

For one in the FIGS. 12 and 13 illustrated alternative embodiment of a connection device 104b is formed as a kind of bayonet connection. In this case, the lid 58 forms radially outwardly oriented web-like wings 106. These wings can be inserted from above into corresponding recesses 107 of the upper end face 108 of the main housing 49, wherein with this insertion movement already a loading of the sealing elements 81, 93 takes place. When the wings 106 engage a bottom 109, the recesses 107, the blades 106 may rotate about the longitudinal axis 66 about the longitudinal axis 66 in circumferentially oriented slots 110 of the end portions of the side wall 57 of the main housing 49. Under certain circumstances, the slots in the end region have an extension 111, so that with movement of the wings 106 in the region of the extensions 111, the lid can be raised again. A step 112 in the transition region from the slot 110 to the extension 111 then secures the lid against inadvertent release, as the release of the lid is only possible when the lid 58 is again pressed slightly downwards. Put simply, the end region of the side wall 57 of the main housing 49 forms hooks 113 in which the wings 106 are received.

For the connection device 104 c, which in the Fig. 14, 15th is shown, is also a kind of bayonet connection used. However, in this case, 57 L-shaped connecting elements 114 are integrally formed on the end region of the side wall, wherein a leg of the L extends in the radial direction, while the other leg extends to form a gap 115 relative to the side wall 57 in the circumferential direction of the main housing 49. In this case, the lid 58 has extending in the direction of the main housing 49 extensions 116 which extend to below the connecting elements 115, are angled inwardly in the direction of the side wall 57 and extend with an end portion upwards again, so that this end portion with a Twist of the lid 58 can be inserted into the gap 115. Here, the radially inwardly extending portion of the extension 116 comes from below to rest against the L-shaped connecting element 114, whereby the lid 58 is secured against lifting upwards.

Finally, the show FIGS. 16 and 17 a connecting element 114d, in which the lid has downwardly extending latching elements 117, which have elastic spring arms 118, which are oriented parallel to the longitudinal axis 66, as well as radially inwardly extending locking lugs 119 have. If the lid is pressed onto the main housing 49, the latching noses 119 snap behind a corresponding shoulder 120 or a latching groove of the main housing 49. Thus, a detent in the radial direction is effected via the latching elements 117. In addition, locking elements 121 are used, which are also formed with spring arms and locking lugs. Here, however, a locking or Rastierwirkung is brought about by an elastic deformation of the spring arms 118 in the circumferential direction and an entry of the locking lugs in circumferentially oriented recesses of the main housing 49th

The lift axle valve is preferably used for a commercial vehicle.

In the event that a plastic is used for the manufacture of a component, which is reinforced with glass fibers, this component is preferably not tensioning or grinding post-processed. Even a deburring can be completely eliminated in this case. The radii and the angles of inclination of the individual surfaces of the components are adapted to the injection molding process, so that a simple removal from a mold is made possible. The same applies to the formation of ribbing and the choice of wall thicknesses.

The illustrated inserts for forming the terminals are formed with metal or plastic, in particular brass inserts, which have a circumferential groove into which a latching element, which is formed by the main housing 49, engage.

Compared with one of the fully milled main housing according to the invention with the use of an injection molding, the wall thicknesses of the main housing 49 are minimized, so that on the one hand due to the light material used and on the other hand due to reduced wall thickness u. U. drastically reduced weight results.

For lift axle valves known from the prior art, the venting connection was arranged in the region of the bottom wall 56 of the lift axle valve 2. This may not apply to the embodiment according to the invention, since in this case the bottom wall of the compression spring 85 is supported on the bottom wall 56, which is preferably in the opposite end of the solenoid valve 3 in order to enable the use of the "sleeve technology" with the sleeves 74th Die Venting is shifted for an embodiment of the invention to the side, which in principle has the disadvantage that a contamination of the vent 15 can be done with dirt particles. In contrast to embodiments according to the prior art, the blind hole 72 u. U. not formed as a through hole. For the prior art, the through hole was equipped with undercuts, in which then the sealing elements of the control edges have occurred for the purpose of bridging the sealing elements. Furthermore, in these undercuts then a hole has opened, which was connected to an associated terminal. In this area, burrs have formed for the prior art, the removal of which has required an increased effort. If such a ridge has not been completely removed, this may have resulted in a serious impairment of the function up to a component failure.

In addition, a radially encircling inner collar 122 of the cover 58 limit the travel of the control piston 10 as a further function. As a further function, a channel for the supply of the supply air with the interposition of the solenoid valve 3 is formed in the cover 58.

A production of the recess for receiving the solenoid valve 3 in the lid 58 can be done using a screw core, which is removed by screwing movement and leaves the finished thread in which the solenoid valve 58 is screwed.

It is possible that the lift axle valve 2 is manufactured in variants with four, six or seven connections. In the simplest case, the Liftachsventil 2 has only four connections, namely the connection for the bellows, the lift bellows, the level control valve and the supply line. Further connections can then be realized via a T-piece. It is also possible that additional connections are provided.

It can also find the same shape use and adaptation to the different number of connections is made by using different cores or sub-cores.

The sealing element 81 can also serve to compensate tolerances for accumulating tolerances of the valve body 73, in particular of the sleeves and the sealing elements. Finally, the sealing element 81 may also be responsible for compensating thermal expansions.

Preferably, the frusto-conical blind hole 72 in the region of the sleeves 74 is formed continuously without a step, so that sleeves 74 of the same diameter can be used. Also in this case, the compensation of the diameter changing over the length due to the conicity of the blind hole 72 by the elastic sealing elements 76, which may have different diameters, but are preferably identical and defies by their elasticity different diameter of the contact surfaces of the blind hole 72 are provided, bring about the desired sealing and control edge effect.

FIGS. 18 and 19 schematically show a connection between a cover 58 and a main housing 49. The cover 58 in this case forms at least one spring arm 123, whose end region forms a radially inwardly protruding latching lug 124. With the spring arm 123 and the latching lug 124, a latching element 130 is formed. In the in FIGS. 18 and 19 shown latched state of the cover 58 with the main housing 49, the locking lug 124 engages behind a step 125, which may also be part of a latching recess or locking groove of the main housing 49. For the illustrated embodiment, both the step 125 and the latching lug are not formed with contact surfaces which are oriented transversely to the longitudinal axis 66. Rather, the contact surfaces are formed at an angle relative to the transverse plane to the longitudinal axis 66. This has the consequence that with the application of forces on the cover 58, which are oriented in the direction of the longitudinal axis 66, but away from the main housing 49, in the region of the contact surfaces between the step 125 and locking lug 124 force components arise which the locking lug 124 radially press outward. Thus, the detent 124 slides for sufficient disassembly forces along the step 125, whereby disassembly is possible. The disassembly forces required for such disassembly can be given constructive particular by shaping the radial stiffness of the spring arm 123 by the cross section and the material of the spring arm 124, the specification of the angle of the contact surfaces between stage 125 and locking lug 124, the design of the friction in the Contact surfaces and the extension of the step 125 transverse to the longitudinal axis 66. If such a simple disassembly by the sole application of disassembly forces not desired, the step 125 may also be oriented transversely to the longitudinal axis 66. In this case, the disassembly of the lid 58 from the main housing 49 requires the use of an additional tool, by means of which the locking lug 124 is spread for disassembly to the outside. In addition, the formation of the stage 125 and the latching nose 124 causes a slope as in the FIGS. 18 and 19 illustrated that a certain tolerance compensation can be done with a prevention of a game, as this may be the case if step 125 and locking lug 124 would be formed with contact surfaces which are oriented transversely to the longitudinal axis 66. Both the step 125 and the locking lug 124 and the spring arm 123 may be circumferentially formed around the longitudinal axis 66 circumferentially or may be arranged only in partial peripheral areas.

According to the embodiment, which in FIGS. 18 and 19 is shown after installation of the cover 58 with the main housing 49 and possibly an additional examination of this connection, in particular with regard to the proper installation and / or tightness of the connection between the cover 58 and main housing 49 and / or an extended functional test, a fuse element 126 use. This hinders in the in Fig. 19 illustrated secured position the elastic degree of freedom of the spring arm 123 with the locking lug 124. For the illustrated embodiment, a recess 127 is formed for this purpose in the lid 58, which in the non-secured position of the fuse element 126 according to Fig. 18 forms a deformation space for the formed with the spring arm 123 and the locking lug 124 latching element. The recess 127 is formed for the illustrated embodiment with a parallel to the longitudinal axis 66 oriented formation or bore or a parallel to the longitudinal axis 66 and circumferentially about the longitudinal axis 66 oriented cutout or molding, wherein the radially inwardly of the recess 127 remaining material of the lid 58 forms the spring arm 123 and the locking lug 124. The securing element 126 has a cross section which correlates with the cross section of the recess 127, so that the securing element 126 can be inserted parallel to the longitudinal axis 66 into the recess 127. In this case, a play, transition or interference fit may be formed between recess 127 and securing element 126. It is also possible that the side surfaces of the recess 127 on the one hand and the securing element 126 are inclined to each other such that with increasing entry of the securing element 126 into the recess 127, the clamping of the securing element 126 in the recess 127 transversely to the longitudinal axis 66 increases, so that spring arm 123 and locking lug 124 are increasingly compressed radially inwardly and the latching connection is strengthened.

Use can be multiple, distributed over the circumference recesses 127, which each engage with a fuse element 126 in operative connection. Here, the fuse elements 126 can be used individually. It is also possible that the securing elements 126, for example, in their outer end region, are interconnected, for example via a rigid or elastic connecting ring, a wire or thread or the like. It is also possible that an additional connection for securing the securing element 126 in the recess 127 is used, for example, a mounting paste, a material connection, for example, with an adhesive agent, or the like.

For that in the FIGS. 20 and 21 illustrated embodiment is not a recess 127, the deformation path for the locking lug 124 and the spring arm 123 before. Rather, the latching lug 124 and the spring arm 123 form the peripheral edge of the lid region which revolves only in partial circumferential areas or in the peripheral direction and which engages over the step 125 with the main housing 49 in the assembled state of the lid 58. In this case, the securing element 126 is designed in the form of a circumferential, for example hollow cylindrical ring 128, which in the in Fig. 20 lower end portion forms an insertion bevel 129 and can be pushed onto the cover 58 from above, so that the ring 128 in the in Fig. 21 illustrated secured position radially outwardly lying the lid 58 surrounds to form a game, transitional or interference fit, possibly also using a kind of spline connection as explained above or use additional security elements, such as a bond.

LIST OF REFERENCE NUMBERS

1

Air suspension system

2

Lifting axle

3

magnetic valve

4

control unit

5

control line

6

magnet

7

feather

8th

exhaust port

9

main body

10

spool

11

piston rod

12

feather

13

spring chamber

14

channel

15

exhaust port

16

control room

17

connection

18

reservoir

19

supply line

20

branch line

21

inlet seat

22

outlet seat

23

valve chamber

24

management

25

connection

26

management

27

lift bag

28

lifting axle

29

Stichkanal

30

bellows

31

connection

32

management

33

connection

34

management

35

Level control valve

36

management

37

bellows

38

carrying axle

39

signal line

40

connection

41

connection

42

3/2-way valve

43

5/2-way valve

44

connection

45

connection

46

connection

47

connection

48

casing

49

main body

50

housing part

51

housing part

52

parting plane

53

base leg

54

side leg

55

side leg

56

bottom wall

57

Side wall

58

cover

59

recess

60

recess

61

recess

62

recess

63

recess

64

extension

65

extension

66

longitudinal axis

67

shell

68

shell

69

inner space

70

step

71

step

72

Blind hole

73

valve body

74

shell

75

groove

76

sealing element

77

spool

78

support sleeve

79

body

80

Federation

81

sealing element

82

step

83

control groove

84

control groove

85

compression spring

86

front

87

sealing element

88

control room

89

chamber

90

Stichkanal

91

spring chamber

92

stub

93

sealing element

94

electrical connection

95

recess

96

drilling

97

Stichkanal

98

cover

99

locking element

100

slot

101

vent body

102

drilling

103

Vent valve seat

104

connecting device

105

locking element

106

wing

107

deepening

108

front

109

ground

110

slot

111

extension

112

step

113

hook

114

connecting element

115

gap

116

extension

117

locking element

118

spring arm

119

locking lug

120

paragraph

121

locking element

122

Federation

123

spring arm

124

locking lug

125

step

126

fuse element

127

recess

128

ring

129

chamfer

130

Valve

131

palm

132

control room

133

through recess

Claims (18)

1. Valve (130), in particular lift axle valve (2) or valve for lifting and lowering, for a pressurized air system of a utility vehicle comprising a housing (48) made of plastic and comprising an inner space (69) wherein a sliding valve body (77) is displaceably guided along a longitudinal axis (66), wherein the sliding valve body (77) in its different positions provides and/or blocks different connections of ports (17; 31; 33) with each other and/or with a vent (15), wherein

   a) the inner space (69) is limited by an inner surface (131) of the housing (48) having the shape of a truncated cone,

   b) at least one sleeve (74) is inserted into the inner space (69) having the inner surface (131) formed by the truncated cone, wherein the sleeve (74)

   ba) radially inside forms at least one control chamber (132) which is connected by at least one radial through recess (133) of the sleeve (74) with at least one port (17; 31; 33) located radially outside from the sleeve (74) or with a vent (15), and

   bb) radially outside forms a gap with the inner surface (131) having the shape of a truncated cone wherein the gap has a height changing in the direction of the longitudinal axis (66) of the sliding valve body (77),

   c) sealing elements (76) of the same construction are supported at the faces of the at least one sleeve (74), wherein the sealing elements (76)

   ca) radially inside cooperate with the sliding valve body (77) for sealing neighboring control chambers (132) and

   cb) radially outside sealingly cooperate with the inner surface (131) of the housing (48) having the shape of a truncated cone, wherein an elasticity of the sealing elements (76) compensates differences of the diameter which are due to the opening angle of the inner surface (131) having the shape of a truncated cone.
2. Valve (130) of claim 1, wherein two or more sleeves (74) are used each having the same diameter wherein a sealing element (76) of the same construction is interposed between the sleeves, wherein the extension of the inner surface (131) having the shape of a truncated cone in the direction of the longitudinal axis (66) is larger than the sum of the extensions of the sleeves (74) in the direction of the longitudinal axis (66).
3. Valve (130) of claim 1 or 2, wherein two or more sleeves (74) having the same construction are used.
4. Valve (130) of one of claims 1 to 3, wherein the plastic material is reinforced by fibres, in particular glass fibres.
5. Valve (130) according to one of claims 1 to 4, wherein the housing (48) is built with

   a) a main housing (49) forming the inner space (69) with the inner surface (131) having the shape of a truncated cone, wherein the main housing (49) is in particular in a first approximation formed pot-like, and

   b) at least one cover (58) closing the main housing.
6. Valve (130) according to claim 5, wherein the cover (58) is built by or with plastic.
7. Valve (130) according to claim 5 or 6, wherein a vent (15) is provided in the region of a side wall (57) of the main housing (49).
8. Valve (130) of claim 7, wherein the vent (15) is built with an insert or cover (98) made of plastic, wherein the insert or cover (98) is connectable with or insertable into a lateral recess (59) of the main housing (49).
9. Valve (130) according to one of claims 1 to 8, wherein the opening angle of the truncated cone of the inner surface (131) is between 0,1° and 2,0°, e.g. between 0,2° and 1,0°.
10. Valve (130) according to one of claims 5 to 9, wherein the inner space (69) is manufactured or molded with a movable core or core mover whereas at least one port (17; 31; 33) being formed transverse to the longitudinal axis and/or a vent (15) is formed by an additional core having a protrusion for forming at least one latching recess in the shape of an undercut or reverse taper, wherein the wall thicknesses of the main housing (49) are dimensioned such that, a stiffness of the plastic material is chosen such that and the at least one protrusion is dimensioned such that it is possible to remove the additional core by a forced removal from the mold out of the solidified plastic material.
11. Valve (130) according to one of claims 5 to 10, wherein the cover (58) closes the main housing (49) and limits the inner space (131).
12. Valve (130) according to one of claims 5 to 11, wherein the cover (58) comprises an accommodation for a magnet valve or solenoid valve (3).
13. Valve (130) according to claim 12, wherein the cover (58) forms a valve seat (22).
14. Valve (130) according to one of claims 5 to 13, wherein the cover (58; 98) is connected with the main housing (49) without use of any screwed connecting elements made of metal.
15. Valve (130) of claim 14, wherein the cover (58; 98) is latched with or upon the main housing (49) or connected with the main housing (49) by a latching connection.
16. Valve (130) of claim 14, wherein the cover (58; 98) is connected with the main housing (49) by a bayonet-connection.
17. Valve (130) according to one of claims 5 to 16, wherein an axial securing and/or an axial pretension or bias of the sleeves (74) and/or the sealing elements (76) interposed between the sleeves (74) is provided by the cover (58; 98).
18. Valve (130) according to one of claims 5 to 17, wherein a sealing element (81) is elastically biased between the cover (58) and the main housing (49), wherein the sealing element (81) besides the provision of a sealing between the cover (58) and the main housing (49) serves for the axial securing and/or axial bias or pretension of the sleeves (74) and the sealing elements (76) interposed between the sleeves (74).

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